脉冲爆震发动机快起爆的二维数值模拟

Two-dimensional numerical simulation for ignition of pulse detonation engine

为研究脉冲爆震发动机的点火过程,用二维欧拉方程和Korobeinikov两步爆震模型对爆震波快起爆过程进行了数值模拟研究。用高温高压未燃气体点火方式来模拟试验中的电火花塞点火。研究表明:电火花塞的能量不足以直接点燃爆震波,爆震波是在经历了一系列反射激波的相互作用后最终建立的。激波 爆震波转捩是快点火过程,是爆震波建立的一个非常重要的机理。在设计点火装置时,火花塞要尽可能靠近壁面和拐角,以便产生高强度的反射激波。同时还要控制反射激波的方向,使之向未燃气体中顺利传播,才能起到很好的点火效果。

Two-dimensional Euler equations and Korobeinikov's two-step detonation model were used to study the strong ignition of pulse detonation engine. Small regions of high pressure and temperature unburnt reactants were used to simulate the electric sparks used in experiments. Simulation shows that the energy of electric sparks is too weak to directly trigger a detonation. The detonation was fully established through a series of interactions and impacts of reflected shock waves. The studies indicate that shock to detonation transition process plays an important role in initiation of pulse detonation engine.